The act of giving or receiving anal sex in an attempt to move a particular piece of obstruction or loosen up the bowel contents of a constipated partner.

This morning, I woke up to my girlfriend loudly grunting and moaning in the bathroom. I asked her what the problem was so when she told me she was constipated, I informed her that if she would go ahead and bend over, I would give her the Sex Lax. Luckily for her, she accepted my offer and now she feels great.